Brooks was rejected by
MI9 and the
Secret Intelligence Service as "too young", but was recruited by the
Special Operations Executive. He was commissioned as a second lieutenant on the General List (without Army pay and allowances) on 9 April 1942. Code named "Alfonse," Brooks was sent to France to aid SOE agent "Robert." The specific task given him was to develop resistance groups among members of
labor unions. His network was called "Pimento." After training, he parachuted into France on 3 July 1942, landing at
St Léonard-de-Noblat, near
Limoges. Brooks refused to be armed because if discovered to possess a firearm (illegal in German-controlled France) his cover story of being an average French citizen would be endangered. Brooks injured his knee and back on landing and might have been captured by French police if not for assistance by a French farmer. After recuperating from his injuries, Brooks paid a brief visit to pioneering SOE agent
Philippe de Vomécourt who had a chateau nearby and then continued on to
Toulouse where he met "Robert" and was delighted to find that Robert was René Bertholet, a Swiss citizen and previous acquaintance. Before returning to Switzerland, Bertholet introduced him to resistance contacts in
Lyon and Brooks also developed contacts in
Montauban. SOE was impatient with Brooks' independence and instructed him to find landing fields for clandestine landings of aircraft and told him that a wireless operator was being sent to him. When the wireless operator,
Marcus Bloom, finally arrived in November, Brooks, who had a well-ingrained sense of security, was appalled on meeting Bloom who was dressed like an Englishman, greeted him in English, and was smoking a pipe of aromatic tobacco unavailable in France. He sent Bloom away to join another SOE network. Bloom was captured by the Germans in 1943 and executed. Brooks would become one of SOE's longest serving agents and would survive World War II, as many SOE agents did not. Brooks, the "mild-mannered and likeable young man turned out to have qualities of imaginative audacity." Later, Brooks also had problems with another agent sent him by SOE:
Lise de Baissac. De Baissac, 38 years old compared to Brook's 22 years, was an experienced and competent agent. She was insulted to serve in the lowly position of Brooks' courier and alienated his socialist and communist contacts with her aristocratic aplomb. The two soon parted company by mutual consent. De Baissac joined her brother
Claude and rendered valuable service in
Normandy before and after the allied invasion of France on
D-Day. Brooks focused on organizing resistance to the Germans among "railwaymen, truck drivers, factory workers, and longshoremen." He constantly traveled, working around both Toulouse and Lyon. Reflecting his attention to security, he rented a
safe house in Lyon that only he knew about. He did not want a wireless operator, vulnerable to German detection, but communicated with SOE headquarters through couriers to neutral Switzerland from where messages could be transmitted to England. In August 1943, SOE ordered Brooks to return to England. He was ill and under great strain. A number of his closest associates had been arrested by the Germans. He left France via clandestine flight on 19 August and stayed in England until 20 December. While in England, he married Hope Munday on 9 November. During his absence André Moch led Pimento.
D-day and beyond Brooks flew back to France in a
RAF Halifax aircraft of
No. 138 Squadron on the night of 20/21 December with a new cover name and the task of stockpiling weapons and explosives for use before and during the expected
American and British invasion of France which would occur on 6 June 1944. The expected invasion also stimulated a large increase in the number of French men and women willing and eager to work in the resistance. Pimento continued its sabotage of transportation and communication facilities to hinder German response to an invasion force. In April 1944, Brooks reported to SOE that he had armed 4,700 men around Toulouse and had another 2,100 men partially armed men in the Lyon region. Brooks' priority before D-day was to inhibit the response of the 15,000 men and 1,400 vehicles of the
2nd SS Panzer Division Das Reich, stationed in Montaubon, to the invasion, wherever and whenever it might occur. The key to success was to disable the railroad
flatcars which would be needed to transport German
tanks quickly to the invasion site. Warned that the invasion was imminent, Pimento operatives sabotaged flatcars by putting an abrasive lubricant into their axles which froze their wheels after a few miles of travel. Historian
Stephen Ambrose tells the story that some of the unguarded flatcars were sabotaged by a 16-year-old girl named Tetty, her boyfriend, her 14-year-old sister, and several of their friends. The transport of Das Reich by railroad to the battlefield in Normandy would have taken three or four days. Instead, Das Reich proceeded northward by road toward the site of the allied invasion on June 7. Its piecemeal arrival at the
Battle of Normandy was between 15 and 30 June and the division was not fully united until July 10. In the three months following D-day, Brooks' forces carried out many attacks and sabotage operations, especially on the railroads. Brooks was wounded slightly when a grenade exploded near him in Lyon. Several of his closest associates were killed in clashes with the Germans. In July, Brooks was arrested in Lyon for the first and only time by the Germans. He was interrogated, but his cover story was convincing and he was released. On being released he exchanged "Heil Hitler" salutes with his captors. Brooks was trapped in Lyon, still German-controlled, while the resistance groups he had aided fought the Germans--and among themselves. Brooks met with American forces advancing into Lyon on 2 September and celebrated the liberation of the city on 3 September with French soldiers. Shortly after the liberation, Brooks was hospitalized with an ulcer. On 25 September 1944 he returned to England, his hazardous service during war completed. Brooks ended the war as a major, and was awarded the
Distinguished Service Order,
Military Cross,
Croix de Guerre with bronze palm, and
Légion d'honneur for his service. ==After the war==